Tìm số nguyên x: x . ( x + 7 ) = 0

1. Tim so nguyen x :
a, x . ( x + 7 ) = 0
b, ( x + 12 ) . ( x - 3 ) = 0
c, ( -x + 5 ) . ( 3 - x ) = 0
d, x . ( 2 + x ) . ( 7 - x ) = 0
e, ( x - 1 ) . ( x + 2 ) . ( -x - 3 ) = 0
Mong cac ban giup !
MINH CAN GAP !!!